Two-cycle internal-combustion engine.



'0. E. MAUD.l `{vwo-mfom 'INTERNAL coMBusTloN ENGINE.

APPLICATION FILED SEPT. 24, 1909.

Patented Dec. 27, 1910.

2:12.2:2 6 w w g# 1 x Z, M n w A M f www@ 7 M au j WTNESSES ATTOHWE YS l To allwhom it may concern:

unirsi) sirarns parlanti; ornion.

antennas4 E. Marimba MONTEREY, CALIFORNIA.

Two-CYCLE m'rnnirancoiuiaus'rioit encina.

Specication et' Letter! Patent.

Patene'anec. 27, 1910.

Application inea september 24, ieee. seriai ne. 519313.

Be itl known that I, CHARLES E. Mann, a citizen of the United States, and a resident of Monterey, in the county of Monterey and State of California, have invented a new and. Improved Two-Cycle Internal-Combustion Engine, of which the following is a full, cleara nd exact description.

This invention relates to certain improvements in two-cycle internal ,combustion engines oi' that type in which the piston serves to separate the explosion chamber from the compression chamber and operates to' commore,

. frusto-conical delectonaiidithe gas is trans press a charge on one side of the piston during the explosion and expansion of; the gases upon the opposite side of the piston. liny engines of this type in which the charge '1s compressed in the crank case, all of the gas cannot be transferred from the `crank case to the cylinder upon the opening of the inlet. port in the latter, and thei'eis therefore a considerable quantity of gas needlessly compressed at one compression Stroke. Further- Wtli the large crankcase chamber, the gas cannot be compressed 4to highl enou h pressure to insure' its proper cylinder 'and the proper scavenging of the cylinder.` Y

` `One object of my invention is to avoid the necessity for compressing any largerV quantity of gas during eachcompression stroke than itis desired to transfer to the Vexplosion l chamber at the end of said stroke. I

, A further object ,of the invention is toinsure the complete' transfer4 to thel cylinder of the compressed charge after the exhaust port is opened and while the' piston is approaching or `at dead center.

My invention involves the provlsion of a separateA movable or operating, `memher,l

which serves to completelyejectthe compressed gas from the compression chamber at the desired instant,'sai member having movement relativew to the piston when the latter is ad'acent the end of Aits power stroke.` The eylin er 'head .pr'erably presents a.

ferred from the lcompression chamber through the center`4 of the'pistn 'and directed toward this deflector. In this way the ex,l haust gas at the upper end and at the sides ofthe cylinder, 1s ,forced outwardly and' downwardly to the exhaust yorts, and the.y

cylinder is completely an thoroughly, scavenged u transfer to t ie.

*mayrif desired sul ferm cfa Spark Vsitiong`ofrtli`is ign f any suitab Reference to be hadto the accompanying drawings, forming a part of this spectication, in which similar characters of refer ence indicate corresponding parts in both the figures, and in which- Figure l is a longitudinal section through anenglne constructed in accordance with -my invention, the power piston being at the end 0f the petrol." Stroke; and Fig. 2 is a section taken Substantially on the line 2-2 of lFig. 1 the power pstonxbeing at the end of its compressionrstroke.

My invention relatesonly to the means for taking in, compressiny and c'lelivering-the explosive charge to,l the" 'cylinder and the scavenging of latter.

form which my'invention may assuniefas variouschanges may be made ywithin the scope of the appeded'clams, without departing 1from the spirit of my invention.

In my improved engine there is employed an enginecylinder 10, having a. working or power piston 1L mounted to reciprocate therein. The cylinder may be of any form or size desired, andmay be cooled in any suitable manner. I have illustrated the cyl.-

inder as provided with a vwater jacket 12,

.a mere skeleton work may serve to form 'a 4bearing for the crank shaft 16 and to su Any suitab e form of piston 'rod 17 conr eets the crank shaft' The power piston; 11 preferably has a skirt or' sleeve 19, of

port the lengine cylinder.

with-the piston pin 1 8.

"a, length slightly greater than its length of trave, andthe interior of this sleeve or skirt is groundl true to constitute a' second" or compressioncylinder,` rlhe lower endjof this skirt or sleeve is connected. to the pis` ton pin, sothat there is a considerableispace esV the exhaust gas from the The en ine illustrated.constitutes only one i )re-directed frusi `This detleetor v45 the explosion chamber.

Vbetween said piston pin and the vhead ofthe 'piston-v i V Within the power piston there is provided j a second piston 20, serving as the rear or lower end of the compression chamber. In

` other words, the gas 1s compressed between fi-the' twov pistons vand :within the peripheral skirt of-'the power piston. The piston 20.

h'as a much shorter travel thanthe power piston, and in fact, it may normally remain stationary, moving toward the power pist0n' to transfer the compressed chargeduring the nal movement of the power stroke 'jiij of the latter. The piston 20 may be oper- 'ated-from the crank shaft`in any suitable manner. One means for securing this movement includes a skirt or sleeve2l on the piston and'concentric with the sleeve 19 of the power piston. This sleeve 21 has a slot 2 0 22 therein to receive the piston pin, and at its lower. end it has extensions 23, terminating adjacent the crank shaft. The crank shaft' is provided with two cams or projec- .tions 24, of such shape and so disposed that I 25 during the rotation of the crank shaft these cams or' projections will engage with the extensions 23 and cause the piston 20 to intermittently reciprocate a limited distance.

V For reducing friction, vthe extensions 23 may l '30 be provided with antifriction rollers25 for ,engagement with the hub of the crank shaft -.`and with the cams, and for causing the rollers to remain at all times in engagement with their operating members, suitable y springs 26 Ymay be provided. These springs .undergo compression during the lifting of the piston 20, and serve to return this piston u after it 'has been raised by the cams. It is, of course, evident that other mechanism mightfbe employed ,for giving to the piston 20,V the desired movement. v

The fuel charge is taken into the space be- A tween the two pistons and thencedelivered through the center of the power piston to The mechanism for feeding the charge to the space between the pistons referablyvincludes one or more conduits 2 each formed of two telescoping sections, The lower section 28 of each conv duit extends out through the base or the pi-ston 20.is provided with a recess in its upper surface in which the valves 31 -are v ,p1aced,so that said valves do not come into engagement with the under surface of the power piston. The power piston has ya port 'extending through the center thereof and rounding the valve is an annular fiange or,

baliie 35, which constitutes a' deflector or guard', and which also serves'the purpose of a nozzle in directing the gases from the compression chamber longitudinally and axially of the cylinder and toward the center of the dome. F or permitting the escape of the exhaustgas after the power piston has completed the major portion of its stroke, the cylinder is provided with one or more exhaust ports 36. Preferably, there are al plurality of these ports arranged around the cylinder, so that the exhaustgas may very freely escape. All of these exhaust ports man connect to a -manifoldor the exhaust gas may be takencare of in any other suitable manner. After the completion vof a power stroke and after the piston reaches dead center, the parts will be in the position indicated in-Fig. l, that is, the power piston is in its .lowermost position and the piston 20 l isl in its uppermost or highest position. As the crank shaft continues to rotate, the power piston rises to cover the exhaust ports -and the cams 24 pass .from beneath the extensions 23, so that the piston 20 moves downwardly to its lowermost position. This separation of 4the two pistons causes a par- -tial vacuum in the space between the two,

and the explosive charge is drawn in through the conduits 27 and past the valves 31. The piston 20 now remains substantial-ly stationary -and the working or power piston continues to move lengthwise of the cylinder, to draw in more charge to the compression space and to compress the charge 1n 'the explosion chamber. Upon the completion vof the compression stroke o f the working piston, the parts reach the position indicated in Fig. 2, and theworlting piston immediately returns under the infiuence of the exploded charge. The valve 33 remains closed during both of these strokes, as the pressure inl the explosion chamber exceeds the pressure in the space between the pistons. WVhen the power piston nearly reaches the lower end of its' stroke, it uncovers the exhaust. ports 86 to permit the escape of the remaining exhaust gas, and immediately'thereafter the cams' 24 strike the rollers 25 and raise the piston 20 towardk the power piston during the completion of the downward m`ove ment ofthe latter. Atthe time the exhaustport opens, the pressure in the cylinder is slightly in excess of that of the compressed charge, but as soon as the exhaust ports have opened, the pressure of the exploded charge immediately drops and the pressure ofthe gas between the pistons overcomes the Atension of the springt opens the valve 33, andfi'sdirected lengthwise and axiall of thefcylinder toward the center, of the t ome or cylinder head. Thegas is transferred to `i5 the cylinder not only by reason of its pres-` 4's ure,v but also by thev bringing of the two pistons together duringpthe final part of the downward movement of the power piston.

'cylinder,.forces the exhaust gas back, down .along the sides ofthe cylinder toward the exhaustports','so that by the time the com- `pressed charge 1s" transferred to the engine' equal to ythe space occupied bythe compressed gases in the cylinder when the power piston is at the end ofits compression stroke and just prior to the ignition. Thus, the

charge transferred. to the cylinder is sufiicient4 to completely fill the latter, w'hich is ,not the case -in an ordinary two-cycle engine havingcrank case compression.

Having thus described my invention, I l claim as new and desire to secure by Letters Patent: l v l l1. An internal combustion engine having a cylinder, a reciprocatory, piston within said cylinder, a second piston forming with the iirst piston a compression chamber, a passage in s aid the deliveryl of gas from said compression chamber to said cylinder, and means for moving said second-mentioned piston substantially into engagement with said firstiimentioned piston to transfer substantially all of the charge through said passage when said first-mentioned piston is Iadjacent the Iend-of its power stroke. y

'2. An internal combustion engine having a cylinder, a piston subdividing the cylinder into an explosion chamber and a compression chamber and operating to compress a Agas in the compressionl chamber during the application of power to the opposite side of the piston, a passage in said piston for the delivery of the gas fromthe compression chamber to the explosionchambe'r, and a member in the rear of the piston 'movable toward said'r-piston and Isubstantially into engagement therewith to transfer substantially all of the gas within the compression chamber to the explosion chamber when said piston ,isl adjacent the end of. its power stroke;

43. An internal combustion engine having a compression chamber and a cylinder inclosing an vexplosion chamber, the maximum capacity of one of said chambers being substantially equal to the maximum capacity of the other, ampiston separating'said cham- "The fresh charge in traveling axially of the This difference in Volume lis approximately first-mentioned piston for la cylinder, a hollow bers and operating to vary ,their relative capacites duringits reciprocation, a second piston formino an end wall for said compression chamber, a passage connecting saidV chambers and means for moving said second piston toward and substantially into engagement with said first-mentionedpiston when said `first-mentioned piston is adjacent the end of its power stroke, to reduce the capacity of the compression chamber approximately to zero andl transfer approximately' the ent-ire compressed `charge to the explosion chamber.

4. 'An internal combustion engine having a cylinder, a reciprocatory hollow vpiston therein provided with a valved passage lead! ing to -the explosion chamber of the engine, a reciprocatory pistonf within. the vfirst-inentioned piston, a fuell conduit leading from the exterior of the engine to the interior yof the first-mentioned piston, and means for moving said second-mentioned piston toward-the head of the first-mentioned piston when the latter is approximately at the end of its power stroke. 5. An internal combustion engine having a cylinder, a reciprocatory hollow power piston therein provided witha passage leading from the interior of .the piston to the interior of the cylinder, and terminating in a deflector within said cylinder and serving for the delivery of, gas to the cylinder, a reciprocatory piston within the 'first-mentioned piston and provided with a valved passage therethrough, and a fuel conduit leading from the exterior of the engine to the last-mentioned passage for the delivery of fuel to the interior ofthe hollow piston;

. 6. An internal combustion engine having 4 a cylinder, a power piston therein, a piston within said power piston, a main shaft for the engine having a cam thereon, an extension from the second-named piston, .terminating in operative relationship to the cam on the shaft, independent'connections between said shaft and the power piston, a

passage for delivering a gas to the interior of the power piston, and a passage for delivering the 'gas from the interior of the power piston to the interior of the cylinder.

7; An internal combustion engine having power piston therein, a piston within the power piston, a shaft having cams in operative relation to the secondmentioned piston, springs constraining the second-named piston toward said cams, a passage for deliveringv a gas to the interior of the power piston, and a passage for delivering the gas from thel interior ofthe power piston to the explosionchamber of the engine.

8. An internal. combustion engine having directed portion, a hollow power piston within said cylinder yhaving a valved passage terminating in an annular defleotor on the explosion chamber side of the piston, a reciprocatory piston within the first-named piston and provided with a Valve/d passage therethrough, and a 'A fuel conduit leading from the exterior of the engine to said valved passage in the second-named piston.

9. An internal combustion engine having a cylinder, a vieciprocatory power piston therein, a piston within the first-named piston, a crank shaft for the engine, a connecting rod pivoted to Said first-mentioned piston and to said crank shaft, cams on said crank shaft for intermittently reciprocating said inner piston, said inner piston remaining stationary during the intervening time between said reciprocations, a passage for .delivering a gas to the space between said pistons, and a passage for delivering said gas from 4said space'to the .interiorvof theAi vcase, piston, crank shaft. and piston rod, of 'a second pistonv within the first-mentioned piston and forming with the first-mentioned piston, a compression chamber, means estab# lishing communiation between Said compression chamber* and the cylinder, and a conduit extending4 through the wall of saidy crank case and communicating with saidl t compression chamber, said yconduit being. .35

formed of two telescoping sections. l In testimony-whereof I have signed my name to this specification in the presence of two subscribing Witnesses. e

CHARLES E. MAUD, W'itnesses:

CLAIR W. FAIRBANK, PHILIP D. RoLLHAUs. 

